Coating compositions can be applied to the interior of food and/or beverage metal cans to prevent the contents from contacting the metal surface of the container. Contact with the container contents can lead to corrosion of the metal container and contamination of the packaged product. Epoxy coatings are typically utilized for metal containers due to their superior performance; however, recently, there has been a desire of the food packaging value chain to explore alternative coating technologies with improved properties for a next generation coating. Polyester resin based systems have been used for many years in some packaging coating applications. However, it has been problematic to formulate polyester systems which exhibit the appropriate balance of properties such as flexibility, chemical and corrosion resistance, and adhesion. This present addresses the shortcomings of polyester resins by defining compositions that exhibit a superior balance of properties for packaging coatings.